1. Field of the Invention
The present invention relates to an image processing apparatus, image processing method, and storage medium, and particularly to a technique of generating, from output data after imaging, reconstruction images.
2. Description of the Related Art
Recently, there has been proposed a technique of storing, as output data, the intensity distribution of light and the incident direction of light at the time of imaging in an image sensing apparatus such as a digital camera, thereby generating, for instance, from the output data after storage, an image focused on an arbitrary subject distance.
Ren.Ng, “Light Field Photography with a Hand-Held Plenoptic Camera”, Stanford University Computer Science Tech Report CTSR 2005-02 discloses a method in which a microlens array is interposed between an imaging lens and an image sensor, and light fluxes incident from various directions are separated and stored by forming images of light fluxes having passed through different divided pupil regions of the imaging lens on the respective pixels (photoelectric conversion elements) of the image sensor through the microlens array. In the obtained output data (Light Field Data: to be referred to as LF data hereinafter), light fluxes incident from different directions are stored in adjacent pixels.
By extracting light fluxes in the same direction from pixels associated with respective microlenses, an image sensed from this direction can be generated from LF data. Also, a method called “Light Field Photography” is applied to set an arbitrary subject distance, and add outputs from pixels which store light fluxes having passed through respective points on a focal plane on which light fluxes from this subject distance converge. As a result, the pixels of an image focused on a specific subject distance can be pseudo-generated (reconstructed) after imaging.
However, reconstruction images focused on various subject distances, or reconstruction images from various viewpoints at a large depth can be generated from the above-mentioned LF data. Hence, privacy information falling within the imaging range may not be appropriately protected.